I just went to some local baby stuff store and got a German-style (i.e. "big") stroller for EUR 100. Lasted for three kids just fine. Not something to take on a plane or a train though, or put in the trunk of a small car.

agree with Marianne013, no need for stool sample, get the anti-Madenwuermer stuff over the counter at the Notapotheke (don't wait, act now), and administer immediately -- with something tasty to go with it. Until I experienced a child getting it i'd never heard of the things, but after learning how easy it is for them to spread it's a wonder all of humanity isn't plagued with them as a standard condition.